Question

This is some Greek and Latin root words for my 6th grade gifted homework. Whats the difference between medicus and medicinal?

Answer 1

"medicus" is the Latin noun meaning doctor.
http://www.etymonline.com/index.php?search=medicus&searchmode=none

"medicinal" is an English adjective.
http://www.etymonline.com/index.php?search=medicinal&searchmode=none
and
http://www.merriam-webster.com/dictionary/medicinal